Display device

ABSTRACT

According to one embodiment, a display device includes a substrate, an insulating layer, a lower electrode, a rib including an aperture and covering a periphery of the lower electrode, a partition above the rib, an upper electrode being in contact with the partition, and an organic layer between the electrodes. The organic layer includes a first organic layer that is in contact with the lower electrode through the aperture, and a second organic layer on the partition. At least a part of the periphery of the lower electrode is located between the insulating layer and the partition in a thickness direction of the insulating layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.18/090,530, filed Dec. 29, 2022, which is based upon and claims thebenefit of priority from Japanese Patent Application No. 2022-001086,filed Jan. 6, 2022, the entire contents of each are incorporated hereinby reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

Recently, display devices with organic light-emitting diodes (OLEDs)applied thereto as display elements have been put into practical use.This display device comprises a lower electrode, an organic layercovering the lower electrode, and an upper electrode covering theorganic layer. Ribs may be arranged to cover the periphery of the lowerelectrode and, in this case, the organic layer and a part of the upperelectrode are formed on the ribs.

Generally, the organic layer and the upper electrode are formed thinlyby vapor deposition. For this reason, if a surface where the organiclayer or the upper electrode is formed has a steep step, the organiclayer or the upper electrode may break off due to this step, resultingin display failure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a configuration example of a display deviceaccording to a first embodiment.

FIG. 2 is a view showing an example of a layout of sub-pixels accordingto the first embodiment.

FIG. 3 is a schematic cross-sectional view showing the display devicetaken along line III-III in FIG. 2 .

FIG. 4 is a schematic enlarged plan view showing a part of FIG. 2 .

FIG. 5 is a schematic cross-sectional view showing the display devicetaken along line V-V in FIG. 4 .

FIG. 6 is a schematic cross-sectional view showing the display devicetaken along line VI-VI in FIG. 4 .

FIG. 7 is a schematic plan view showing a sub-pixel according to asecond embodiment.

FIG. 8 is a schematic plan view showing a sub-pixel according to a thirdembodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device includes asubstrate; an insulating layer arranged above the substrate; a lowerelectrode arranged above the insulating layer; a rib formed of aninorganic material, including an aperture which overlaps with the lowerelectrode, and covering a periphery of the lower electrode; a partitionarranged above the rib; an upper electrode opposed to the lowerelectrode and being in contact with the partition; and an organic layerlocated between the lower electrode and the upper electrode to emitlight in accordance with a potential difference between the lowerelectrode and the upper electrode. The organic layer includes a firstorganic layer that is in contact with the lower electrode through theaperture, and a second organic layer located on the partition andseparated from the first organic layer. At least a part of the peripheryof the lower electrode is located between the insulating layer and thepartition in a thickness direction of the insulating layer.

According to this configuration, a display device capable of allowingthe display quality to be improved can be provided.

Several embodiments will be described hereinafter with reference to theaccompanying drawings.

The disclosure is merely an example, and proper changes in keeping withthe spirit of the invention, which are easily conceivable by a person ofordinary skill in the art, come within the scope of the invention as amatter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc., of therespective parts are schematically illustrated in the drawings, comparedto the actual modes. However, the schematic illustration is merely anexample, and adds no restrictions to the interpretation of theinvention. In addition, in the specification and drawings, structuralelements which function in the same or a similar manner to thosedescribed in connection with preceding drawings are denoted by likereference numbers, detailed description thereof being omitted unlessnecessary.

In the drawings, an X-axis, a Y-axis and a Z-axis orthogonal to eachother are described to facilitate understanding as needed. A directionalong the X-axis is referred to as a first direction X, a directionalong the Y-axis is referred to as a second direction Y, and a directionalong the Z-axis is referred to as a third direction Z. Viewing variouselements parallel to the third direction Z is referred to as planarview.

The display device of each of the embodiments is an organicelectroluminescent display device comprising an organic light emittingdiode (OLED) as a display element, and can be mounted on televisions,personal computers, vehicle-mounted devices, tablet terminals,smartphones, cell phone terminals, and the like.

First Embodiment

FIG. 1 is a plan view showing a configuration example of a displaydevice DSP according to the embodiment. The display device DSP has adisplay area DA where images are displayed and a surrounding area SAaround the display area DA, on an insulating substrate 10. The substrate10 may be glass or a flexible resin film.

In the embodiment, the shape of the substrate 10 in planar view is arectangular shape. However, the shape of the substrate 10 in planar viewis not limited to a rectangular shape, but may be any other shape suchas a square, a circle or an ellipse.

The display area DA includes a plurality of pixels PX arrayed in amatrix in the first direction X and the second direction Y. Each of thepixels PX includes a plurality of sub-pixels SP. In one example, thepixel PX includes a red sub-pixel SP1 (first sub-pixel), a greensub-pixel SP2 (second sub-pixel) and a blue sub-pixel SP3 (thirdsub-pixel). The pixel PX may include sub-pixels SP of other colors suchas a white color together with the sub-pixels SP1, SP2, and SP3 orinstead of any of the sub-pixels SP1, SP2, and SP3.

The sub-pixel SP comprises a pixel circuit 1 and a display element 20driven by the pixel circuit 1. The pixel circuit 1 comprises a pixelswitch 2, a drive transistor 3, and a capacitor 4. The pixel switch 2and the drive transistor 3 are, for example, switching elementsconstituted by thin-film transistors.

A gate electrode of the pixel switch 2 is connected to a scanning lineGL. One of a source electrode and a drain electrode of the pixel switch2 is connected to a signal line SL, and the other is connected to a gateelectrode of the drive transistor 3 and the capacitor 4. In the drivetransistor 3, one of the source electrode and the drain electrode isconnected to the power line PL and the capacitor 4, and the other isconnected to the display element 20.

The configuration of the pixel circuit 1 is not limited to the exampleshown in the figure. For example, the pixel circuit 1 may comprise morethin-film transistors and capacitors.

The display element 20 is an organic light emitting diode (OLED) servingas a light emitting element. For example, the sub-pixel SP1 comprises adisplay element 20 that emits light of a red wavelength range, thesub-pixels SP2 comprises a display element that emits light of a greenwavelength range, and the sub-pixels SP3 comprises a display element 20that emits light of a blue wavelength range.

FIG. 2 is a view showing an example of a layout of the sub-pixels SP1,SP2, and SP3. In the example of FIG. 2 , the sub-pixels SP1 and SP2 arearranged in the second direction Y. Furthermore, each of the sub-pixelsSP1 and SP2 is arranged with the sub-pixels SP3 in the first directionX.

When the sub-pixels SP1, SP2, and SP3 are arranged in such a layout, arow in which the sub-pixels SP1 and SP2 are alternately arranged in thesecond direction Y and a row in which a plurality of sub-pixels SP3 arerepeatedly arranged in the second direction Y are formed in the displayarea DA. These rows are alternately arranged in the first direction X.

The layout of the sub-pixels SP1, SP2, and SP3 is not limited to theexample in FIG. 2 . As another example, the sub-pixels SP1, SP2, and SP3in each pixel PX may be arranged in order in the first direction X.

A rib 5 and a partition 6 are arranged in the display area DA. The rib 5includes apertures AP1, AP2, and AP3 in the sub-pixels SP1, SP2, andSP3, respectively. In the example shown in FIG. 2 , the aperture AP2 islarger than the aperture AP1, and the aperture AP3 is larger than theaperture AP2.

The partition 6 overlaps with the rib 5 in planar view. The partition 6includes a plurality of first partitions 6 x extending in the firstdirection X and a plurality of second partitions 6 y extending in thesecond direction Y. The plurality of first partitions 6 x are locatedbetween the apertures AP1 and AP2 adjacent in the second direction Y andbetween two apertures AP3 adjacent in the second direction Y. The secondpartitions 6 y are located between the apertures AP1 and AP3 adjacent inthe first direction X and between the apertures AP2 and AP3 adjacent inthe first direction X.

In the example in FIG. 2 , the first partitions 6 x and the secondpartitions 6 y are connected to each other. Thus, the partition 6 has agrating pattern surrounding the apertures AP1, AP2, and AP3 as a whole.The partition 6 is considered to include apertures at the sub-pixelsSP1, SP2, and SP3, similarly to the rib 5.

The sub-pixel SP1 comprises a lower electrode LE1, an upper electrodeUE1, and an organic layer OR1 each overlapping with the aperture AP1.The sub-pixel SP2 comprises a lower electrode LE2, an upper electrodeUE2, and an organic layer OR2 each overlapping with the aperture AP2.The sub-pixel SP3 comprises a lower electrode LE3, an upper electrodeUE3, and an organic layer OR3 each overlapping with the aperture AP3. Inthe example shown in FIG. 2 , outer shapes of the upper electrode UE1and the organic layer OR1 correspond to each other, outer shapes of theupper electrode UE2 and the organic layer OR2 correspond to each other,and outer shapes of the upper electrode UE3 and the organic layer OR3correspond to each other.

The lower electrode LE1, the upper electrode UE1, and the organic layerOR1 constitute the display element 20 of the sub-pixel SP1. The lowerelectrode LE2, the upper electrode UE2, and the organic layer OR2constitute the display element 20 of the sub-pixel SP2. The lowerelectrode LE3, the upper electrode UE3, and the organic layer OR3constitute the display element 20 of the sub-pixel SP3.

The lower electrode LE1 is connected to the pixel circuit 1 of thesub-pixel SP1 (see FIG. 1 ) through a contact hole CH1. The lowerelectrode LE2 is connected to the pixel circuit 1 of the sub-pixel SP2through a contact hole CH2. The lower electrode LE3 is connected to thepixel circuit 1 of the sub-pixel SP3 through the contact hole CH3.

The contact holes CH1 and CH2 entirely overlap with the first partition6 x between the apertures AP1 and AP2 adjacent in the second directionY. The contact hole CH3 entirely overlaps with the first partition 6 xbetween two apertures AP3 adjacent in the second direction Y.

In the example in FIG. 2 , the lower electrodes LE1 and LE2 includeprotrusions PR11 and PR21 (first protrusions), respectively. Theprotrusion PR11 protrudes from a main body of the lower electrode LE1(portion overlapping with the aperture AP1) toward the contact hole CH1.The protrusion PR21 protrudes from a main body of the lower electrodeLE2 (portion overlapping with the aperture AP2) toward the contact holeCH2. The contact holes CH1 and CH2 overlap with the protrusions PR11 andPR21, respectively.

FIG. 3 is a schematic cross-sectional view showing the display deviceDSP taken along line III-III in FIG. 2 . A circuit layer 11 is arrangedon the substrate 10 described above. The circuit layer 11 includesvarious circuits and lines such as the pixel circuits 1, the scanninglines GL, the signal lines SL and the power lines PL shown in FIG. 1 .The circuit layer 11 is covered with an insulating layer 12. Theinsulating layer 12 functions as a planarization film for planarizinguneven parts generated by the circuit layer 11. Although not shown inthe cross section of FIG. 3 , the contact holes CH1, CH2, and CH3 areprovided in the insulating layer 12.

The lower electrodes LE1, LE2, and LE3 are arranged on the insulatinglayer 12. The rib 5 is arranged on the insulating layer 12 and the lowerelectrodes LE1, LE2, and LE3. End parts of the lower electrodes LE1,LE2, and LE3 are covered with the rib 5.

The partition 6 includes a lower portion 61 arranged on the rib 5 and anupper portion 62 that covers an upper surface of the lower portion 61.The upper portion 62 has a width greater than the lower portion 61. As aresult, both the end parts of the upper 62 protrude beyond the sidesurfaces of the lower portion 61 in FIG. 3 . This shape of the partition6 is referred to as overhanging.

The organic layer OR1 shown in FIG. 2 includes a first organic layer OR1a and a second organic layer OR1 b that are separated from each other.In addition, the upper electrode UE1 shown in FIG. 2 includes a firstupper electrode UE1 a and a second upper electrode UE1 b that areseparated from each other. As shown in FIG. 3 , the first organic layerOR1 a is in contact with the lower electrode LE1 through the apertureAP1 and covers a part of rib 5. The second organic layer OR1 b islocated on the upper portion 62. The first upper electrode UE1 a isopposed to the lower electrode LE1 and covers the first organic layerOR1 a. Furthermore, the first upper electrode UE1 a is in contact withthe side surface of the lower portion 61. The second upper electrode UE1b is located on the partition 6 and covers the second organic layer OR1b.

The organic layer OR2 shown in FIG. 2 includes a first organic layer OR2a and a second organic layer OR2 b that are separated from each other.In addition, the upper electrode UE2 shown in FIG. 2 includes a firstupper electrode UE2 a and a second upper electrode UE2 b that areseparated from each other. As shown in FIG. 3 , the first organic layerOR2 a is in contact with the lower electrode LE2 through the apertureAP2 and covers a part of the rib 5. The second organic layer OR2 b islocated on the upper portion 62. The first upper electrode UE2 a isopposed to the lower electrode LE2 and covers the first organic layerOR2 a. Furthermore, the first upper electrode UE2 a is in contact withthe side surface of the lower portion 61. The second upper electrode UE2b is located above the partition 6 and covers the second organic layerOR2 b.

The organic layer OR3 shown in FIG. 2 includes a first organic layer OR3a and the second organic layer OR3 b that are separated from each other.In addition, the upper electrode UE3 shown in FIG. 2 includes a firstupper electrode UE3 a and a second upper electrode UE3 b that areseparated from each other. As shown in FIG. 3 , the first organic layerOR3 a is in contact with the lower electrode LE3 through the apertureAP3 and covers a part of the rib 5. The second organic layer OR3 b islocated on the upper portion 62. The first upper electrode UE3 a isopposed to the lower electrode LE3 and covers the first organic layerOR3 a. Furthermore, the first upper electrode UE3 a is in contact withthe side surface of the lower portion 61. The second upper electrode UE3b is located above the partition 6 and covers the second organic layerOR3 b.

Sealing layers 71, 72, and 73 are arranged in the sub-pixels SP1, SP2,and SP3, respectively. The sealing layer 71 continuously covers thefirst upper electrode UE1 a, the side surface of the lower portion 61,and the second upper electrode UE1 b. The sealing layer 72 continuouslycovers the first upper electrode UE2 a, the side surface of the lowerportion 61, and the second upper electrode UE2 b. The sealing layer 73continuously covers the first upper electrode UE3 a, the side surfacesof the lower portion 61, and the second upper electrode UE3 b.

In the example in FIG. 3 , the second organic layer OR1 b, the secondupper electrode UE1 b, and the sealing layer 71 on the partition 6between the sub-pixels SP1 and SP3 are separated from the second organiclayer OR3 b, the second upper electrode UE3 b, and the sealing layer 73on this partition 6. In addition, the second organic layer OR2 b, thesecond upper electrode UE2 b, and the sealing layer 72 on the partition6 between the sub-pixels SP2 and SP3 are separated from the secondorganic layer OR3 b, the second upper electrode UE3 b, and the sealinglayer 73 on this partition 6.

The sealing layers 71, 72, and 73 are covered with a resin layer 13. Theresin layer 13 is covered with a sealing layer 14. Furthermore, thesealing layer 14 is covered with a resin layer 15.

The insulating layer 12 and the resin layers 13 and 15 are formed of anorganic material. The rib 5 and the sealing layers 14, 71, 72, and 73are formed of, for example, an inorganic material such as siliconnitride (SiNx).

The lower portion 61 of the partition 6 is conductive. The upper portion62 of the partition 6 may also be conductive. The lower electrodes LE1,LE2, and LE3 may be formed of a transparent conductive material such asITO and may have a multilayer structure of a metallic material such assilver (Ag) and a transparent conductive material. The upper electrodesUE1, UE2, and UE3 are formed of, for example, a metallic material suchas an alloy (MgAg) of magnesium and silver. The upper electrodes UE1,UE2, and UE3 may be formed of a transparent conductive material such asITO.

When potentials of the lower electrodes LE1, LE2, and LE3 are relativelyhigher than those of the upper electrodes UE1, UE2, and UE3, the lowerelectrodes LE1, LE2, and LE3 correspond to anodes, and the upperelectrodes UE1, UE2, and UE3 correspond to cathodes. In addition, whenthe potentials of the upper electrodes UE1, UE2, and UE3 are relativelyhigher than those of the lower electrodes LE1, LE2, and LE3, the upperelectrodes UE1, UE2, and UE3 correspond to anodes, and the lowerelectrodes LE1, LE2, and LE3 correspond to cathodes.

The organic layers OR1, OR2, and OR3 include a pair of functional layersand a light emitting layer interposed between these functional layers.As an example, each of the organic layers OR1, OR2, and OR3 includes astructure in which a hole-injection layer, a hole-transport layer, anelectron blocking layer, an emitting layer, a hole blocking layer, anelectron-transport layer, and an electron-injection layer are stacked inthis order.

The sub-pixels SP1, SP2, and SP3 may further include cap layers foradjusting the optical characteristics of the light emitted from theemitting layers of the organic layers OR1, OR2, and OR3. Such a caplayer may be formed between the upper electrode UE1 and the sealinglayer 71, between the upper electrode UE2 and the sealing layer 72, andbetween the upper electrode UE3 and the sealing layer 73.

A common voltage is supplied to the partition 6. This common voltage issupplied to each of the first upper electrodes UE1 a, UE2 a, and UE3 athat are in contact with the side surfaces of the lower portion 61. Apixel voltage is supplied to the lower electrodes LE1, LE2, and LE3through the pixel circuits 1 included in the respective sub-pixels SP1,SP2, and SP3.

When a potential difference is formed between the lower electrode LE1and the upper electrode UE1, the emitting layer of the first organiclayer OR1 a emits light of the red wavelength range. When a potentialdifference is formed between the lower electrode LE2 and the upperelectrode UE2, the emitting layer of the first organic layer OR2 a emitslight of the green wavelength range. When a potential difference isformed between the lower electrode LE3 and the upper electrode UE3, theemitting layer of the first organic layer OR3 a emits light of the bluewavelength range.

As another example, the emitting layers of the organic layers OR1, OR2,and OR3 may emit light of the same color (for example, white). In thiscase, the display device DSP may comprise color filters that convert thelight emitted from the emitting layers into light of the colorscorresponding to the sub-pixels SP1, SP2, and SP3. In addition, thedisplay device DSP may comprise color filters that are excited by thelight emitted from the emitting layers and generate the light of thecolors corresponding to the sub-pixels SP1, SP2, and SP3.

The thickness of the rib 5 formed of an inorganic material issufficiently small as compared to the thickness of the partition 6 andthe insulating layer 12. The thickness of each of the lower electrodesLE1, LE2, and LE3 and the organic layers OR1, OR2, and OR3 is smallerthan the thickness of the rib 5. In addition, the thickness of each ofthe upper electrodes UE1, UE2, and UE3 is smaller than the thickness ofthe rib 5 and the thickness of the lower electrodes LE1, LE2, and LE3.

The thickness of the rib 5 is, for example, 200 nm or more and 400 nm orless. The thickness of the lower electrodes LE1, LE2, and LE3 is, forexample, a half or less of the thickness of the ribs 5. The thickness ofthe upper electrodes UE1, UE2, and UE3 is, for example, a half or lessor a quarter or less of the thickness of the lower electrodes LE1, LE2,and LE3.

FIG. 4 is an enlarged schematic plan view showing the vicinity of thesub-pixel SP1 in FIG. 2 . A part overlapping with the partition 6, ofthe area surrounded by a chain line showing outlines of the upperelectrode UE1 and the organic layer OR1, corresponds to the second upperelectrode UE1 b and the second organic layer OR1 b described above.Furthermore, a part located inside the second upper electrode UE1 b andthe second organic layer OR1 b, of the area surrounded by the chainline, corresponds to the first upper electrode UE1 a and the firstorganic layer OR1 a described above.

The second upper electrode UE1 b and the second organic layer OR1 bsurround the first upper electrode UE1 a, the first organic layer OR1 a,and the aperture AP1. Similarly, the second upper electrode UE2 b andthe second organic layer OR2 b shown in FIG. 3 surround the first upperelectrode UE2 a, the first organic layer OR2 a, and the aperture AP2. Inaddition, the second upper electrode UE3 b and the second organic layerOR3 b shown in FIG. 3 surround the first upper electrode UE3 a, thefirst organic layer OR3 a, and the aperture AP3.

In the embodiment, the entire contact hole CH1 overlaps with the firstpartition 6 x. The contact hole CH1 is located between the organiclayers OR1 and OR2 (or between the upper electrodes UE1 and UE2) in thesecond direction Y.

The first partition 6 x overlapping with the contact hole CH1 has awidth Wx1 in the second direction Y. The first partition 6 x that doesnot overlap with the contact hole CH1 (first partition 6 x on an upperside in the figure) has a width Wx2. Each of the second partitions 6 yhas a width Wy in the first direction X. In the example in FIG. 4 , thewidth Wx1 is larger than the width Wx2 and the width Wy (Wx1>Wx2, Wy).As an example, the width Wy is equal to the width Wx2.

The periphery (outline) of the lower electrode LE1 has a first side S11,a second side S12, a third side S13, and a fourth side S14. The firstside S11 extends in the first direction X. The second side S12 islocated on a side opposite to the first side S11 in the second directionY and extends in the first direction X. The third side S13 extends inthe second direction Y. The fourth side S14 is located on a sideopposite to the third side S13 in the first direction X and extends inthe second direction Y.

The first side S11 is located between the contact holes CH1 and theaperture AP1 in the second direction Y and overlaps with the firstpartition 6 x on a lower side of the figure. The protrusion PR11protrudes from the first side S11 toward the lower electrode LE2 andoverlaps with the contact hole CH1.

In the example of FIG. 4 , the second side S12 is located between theaperture AP1 and the first partition 6 x on the upper side of thefigure, in the second direction Y. In other words, the second side S12does not overlap with the partition 6. The third side S13 is locatedbetween the aperture AP1 and the second partition 6 y on the left sideof the figure, in the first direction X. The fourth side S14 is locatedbetween the aperture AP1 and the second partition 6 y on the right sideof the figure, in the first direction X. Parts of the third side S13 andthe fourth side S14 overlap with the first partition 6 x, but theremaining portions do not overlap with the partition 6.

The first partition 6 x with which the contact hole CH1 overlaps alsooverlaps with the entire contact hole CH2. The contact hole CH2 islocated between the organic layers OR1 and OR2 (or between the upperelectrodes UE1 and UE2) in the second direction Y. The contact holes CH1and CH2 are arranged in the first direction X. The lower electrode LE2has a first side S21 that overlaps with this first partition 6 x. Mostof the other sides of the lower electrode LE2 do not overlap with thepartition 6, similarly to the sides S12, S13, and S14 of the lowerelectrode LE1. The protrusion PR21 protrudes from the first side S21toward the lower electrode LE1 and overlaps with the contact hole CH2.Although not shown in FIG. 4 , as regards the lower electrode LE3, too,one side adjacent to the contact hole CH3 overlaps with the firstpartition 6 x, and most of the other sides do not overlap with thepartition 6.

FIG. 5 is a schematic cross-sectional view showing the display deviceDSP taken along line V-V in FIG. 4 . In this figure, the substrate 10,the resin layers 13 and 15, and the sealing layer 14 shown in FIG. 3 areomitted.

The contact hole CH1 penetrates the insulating layer 12. The protrusionPR11 of the lower electrode LE1 is in contact with a conductive layer CLincluded in the circuit layer 11 through the contact hole CH1. Theconductive layer CL corresponds to, for example, a source electrode or adrain electrode of the drive transistor 3 shown in FIG. 1 .

The lower portion 61 of the first partition 6 x (partition 6) has sidesurfaces 61 a and 61 b. The first upper electrode UE1 a is in contactwith a part of the side surface 61 a. The other part of the side surface61 a is covered with the sealing layer 71. Similarly, the first upperelectrode UE2 a is in contact with a part of the side surface 61 b. Theother part of the side surface 61 b is covered with the sealing layer72.

The upper portion 62 of the first partition 6 x includes an end part 62a protruding from the side surface 61 a and an end part 62 b protrudingfrom the side surface 61 b. In the example in FIG. 5 , the sealing layer71 covers a lower surface of the end part 62 a, and the sealing layer 72covers a lower surface of the end part 62 b.

The second organic layers OR1 b and OR2 b located on the first partition6 x are spaced apart in the second direction Y. Similarly, the secondupper electrodes UE1 b and UE2 b located on the first partition 6 x arespaced apart in the second direction Y. Furthermore, an end part 71 a ofthe sealing layer 71 and an end part 72 a of the sealing layer 72 arelocated on the first partition 6 x and are spaced apart in the seconddirection Y.

In the embodiment, since the rib 5 is sufficiently thinner than theinsulating layer 12, the rib 5 is depressed above the contact hole CH1and a recess RS1 is formed. Furthermore, the first partition 6 xarranged on the rib 5 is also depressed above the contact hole CH1, anda recess RS2 is formed.

The side surfaces 61 a and 61 b are located outside the recess RS1. Inother words, the lower portion 61 covers an entire inner surface of therecess RS1 and also covers a flat upper surface of the rib 5 around therecess RS1.

The side surface 61 a is located between the contact hole CH1 and theaperture AP1 in the second direction Y. The side surface 61 b is locatedbetween the contact hole CH2 and the aperture AP2 (see FIG. 4 ) in thesecond direction Y.

A distance between the side surface 61 a and the contact hole CH1(opening in the lower surface of the insulating layer 12) is defined asD1, a distance between the side surface 61 b and the contact hole CH1(above-mentioned opening) is defined as D2, and a width of the contacthole CH1 (above-mentioned opening) in the second direction Y is definedas Wc.

The distance D1 is, for example, 2.0 μm or more and, desirably, 4.5 μmor more from the viewpoint of forming the organic layer OR1 and theupper electrode UE1 in a desirable shape. The width Wc is, for example,3 μm or more and 5 μm or less. In the example in FIG. 5 , the width Wcis larger than the distance D1, and the distance D2 is larger than thewidth Wc (D1<Wc<D2). The distance and the width are not limited to thisbut, for example, the distance D1 may be larger than the width Wc.

The cross-sectional structure in the vicinity of the contact holes CH2and CH3 is the same as the cross-sectional structure in the vicinity ofthe contact hole CH1 shown in FIG. 5 . In other words, a distancebetween the contact holes CH2 and CH3 and the side surfaces 61 a and 61b of the first partition 6 x overlapping the holes is, for example, 2.0μm or more and, desirably, 4.5 μm or more.

FIG. 6 is a schematic cross-sectional view showing the display deviceDSP taken along line VI-VI in FIG. 4 . In this figure, like FIG. 5 , thesubstrate 10, the resin layers 13 and 15, and the sealing layer 14 areomitted.

In the embodiment, since the rib 5 is thin, stepped portions caused bythe lower electrodes LE1, LE2, and LE3 are formed on the upper surfaceof the rib 5. For example, in the example in FIG. 6 , a stepped portion5 a is formed on the rib 5 in the vicinity of the first side S11 of thelower electrode LE1. In addition, a stepped portion 5 b is formed on therib 5 in the vicinity of the first side S21 of the lower electrode LE2.Similar stepped portions 5 a and 5 b are also formed in the crosssection of FIG. 5 .

In the embodiment, as shown in FIG. 4 , the first side S11 and theprotrusion PR11 entirely overlap with the first partition 6 x. In otherwords, as shown in FIG. 5 and FIG. 6 , the first side S11 and theprotrusion PR11 are located between the insulating layer 12 and thefirst partition 6 x (lower portion 61) in the third direction Z(thickness direction of the rib 5 and the insulating layer 12). Thestepped portion 5 a generated by the first side S11 and the protrusionPR11 is thereby covered with the first partition 6 x.

Similarly, the first side S21 and the protrusion PR21 of the lowerelectrode LE2 are located between the insulating layer 12 and the firstpartition 6 x (lower portion 61) in the third direction Z. The steppedportion 5 b generated by the first side S21 and the protrusion PR21 isthereby covered with the first partition 6 x.

As shown in FIG. 2 , in the sub-pixel SP3, too, the side in the vicinityof the contact hole CH3, of the periphery of the lower electrode LE3overlaps with the first partition 6 x. The stepped portions of the rib 5generated by the sides are thereby covered with the first partition 6 x.

When forming the organic layer OR1, the material which is to be a basethereof is first deposited over the entire display area DA. At thistime, the material is divided into the first organic layer OR1 a and thesecond organic layer OR1 b by the partition 6. Next, the material thatis to be a base of the upper electrode UE1 is deposited over the entiredisplay area DA. At this time, the material is divided into the firstupper electrode UE1 a and the second upper electrode UE1 b by thepartition 6.

Since the organic layer OR1 and the upper electrode UE1 that are thusformed by vapor deposition are thin, they may be divided by the steppedportion 5 a of the rib 5. For example, in the vicinity of the secondside S12, the third side S13, and the fourth side S14 shown in FIG. 4 ,the first organic layer OR1 a and the first upper electrode UE1 a can bebroken by the stepped portion 5 a generated by the sides.

The breakage of the first organic layer OR1 a and the first upperelectrode UE1 a may be a cause of display failure. In particular, whenthe breakage of the first upper electrode UE1 a occurs over a wide area,a voltage may not be sufficiently supplied from the partition 6 to thefirst upper electrode UE1 a. If the first upper electrode UE1 a iscompletely separated from the partition 6, the sub-pixel SP1 cannotlight up.

With respect to this point, in the embodiment, the stepped portion 5 agenerated by the first side S11 is covered with the first partition 6 x.The breakage of the first upper electrode UE1 a is thereby suppressed atleast in the vicinity of the first side S11. As a result, a voltage canbe desirably supplied from the partition 6 to the first upper electrodeUE1 a and the display quality of the display device DSP can be improved.

The advantages of the embodiment have been described by focusing thestepped portion 5 a generated by the lower electrode LE1, and theorganic layer OR1 and the upper electrode UE1, but the same advantagescan be obtained by the organic layers OR2 and OR3 and the upperelectrodes UE2 and UE3 in the structure of the embodiment. In addition,the structure in which the stepped portion 5 a generated by the firstside S11 is covered with the first partition 6 x may also be applied tothe vicinities of the second side S12, the third side S13, and thefourth side S14. In other words, if at least one side of the steppedportion 5 generated by the lower electrode LE, of the first side, thesecond side, the third side, and the fourth side of the pixel, iscovered with the partition 6, the breakage of the upper electrode UE inthe vicinity of the side can be suppressed and a voltage can bedesirably suppled from the partition 6 to the upper electrode UE.

Second and third embodiments of the display device DSP will be disclosedbelow. In these embodiments, differences from the first embodiment willbe mainly focused, and descriptions of the same configuration as thefirst embodiment will be omitted.

Second Embodiment

FIG. 7 is a schematic plan view showing a sub-pixel SP1 provided in adisplay device DSP according to a second embodiment, and a structure ofits surrounding. In an example of this figure, a first side S11 of alower electrode LE1 and a first side S21 of a lower electrode LE2 do notoverlap with a partition 6. In contrast, protrusions PR11 and PR21overlap with a first partition 6 x and have a larger size than theexample in FIG. 4 .

A stepped portion of a rib 5 caused by the lower electrodes LE1 and LE2is not generated on protrusions PR11 and PR21 except for peripheries ofthe protrusions PR11 and PR21. For this reason, an area where firstupper electrodes UE1 a and UE2 a are made desirably conductive with thefirst partition 6 x can be widely secured by enlarging the protrusionsPR11 and PR21, and the same advantages as those of the first embodimentcan be achieved.

As shown in FIG. 7 , a width of the lower electrode LE1 in the firstdirection X is defined as W11, and a width of the protrusion PR11 in thefirst direction X is defined as W12. In addition, a width of the lowerelectrode LE2 in the first direction X is defined as W21, and a width ofthe protrusion PR21 in the first direction X is defined as W22.

The width W12 is desirably one third or more of the width W11.Similarly, the width W22 is desirably one third or more of the widthW21. In one example, the widths W11 and W21 are equal to each other, andthe widths W12 and W22 are equal to each other.

An interval needs to be formed between the protrusions PR11 and PR21 inorder to suppress the conduction of the lower electrodes LE1 and LE2.For this reason, for example, the width W12 is less than a half of thewidth W11, and the width W22 is less than a half of the width W21.

Third Embodiment

FIG. 8 is a schematic plan view showing a sub-pixel SP1 provided in adisplay device DSP according to a third embodiment, and a structure ofits surrounding. In the example of this figure, first partitions 6 xoverlapping with contact holes CH1 and CH2 include protrusions PR12 andPR22 (second protrusions) that protrude toward apertures AP1 and AP2,respectively.

A part of a first side S11 of a lower electrode LE1 overlaps with theprotrusion PR12, and a remaining part does not overlap with a firstpartition 6 x. In addition, a part of the first side S21 of the lowerelectrode LE2 overlaps with a protrusion PR22, and a remaining part doesnot overlap with the first partition 6 x. In other words, in the exampleof FIG. 8 , a part of the first side S11 is located between aninsulating layer 12 and the protrusion PR12 in the third direction Z,and a part of the first side S21 is located between the insulating layer12 and the protrusion PR22 in the third direction Z. As another example,the entire first side S11 may be located between the insulating layer 12and the protrusion PR12. In addition, the entire first side S21 may belocated between the insulating layer 12 and the protrusion PR22.

Thus, an area where first upper electrodes UE1 a and UE2 a are madedesirably conductive with the first partition 6 x can also be secured bycovering the peripheries of the lower electrodes LE1 and LE2 are coveredwith protrusions PR12 and PR22, and the same advantages as those of thefirst embodiment can be achieved.

As shown in FIG. 8 , a width of the lower electrode LE1 in the firstdirection X is defined as W11, and a width of a portion of the lowerelectrode LE1 that overlaps with the protrusion PR12 (portion locatedbetween the insulating layer 12 and the protrusion PR12) is defined asW13. In addition, a width of the lower electrode LE2 in the firstdirection X is defined as W21, and a width of a portion of the lowerelectrode LE2 that overlaps with the protrusion PR22 (portion locatedbetween the insulating layer 12 and the protrusion PR22) is defined asW23.

The width W13 is desirably one third or more of the width W11.Similarly, the width W23 is desirably one third or more of the widthW21. In one example, the widths W11 and W21 are equal to each other, andthe widths W13 and W23 are equal to each other.

In the first to third embodiments, the configuration in which the firstside S11 or the protrusion PR11, of the periphery of the lower electrodeLE1, is located between the insulating layer 12 and the partition 6 hasbeen exemplified. However, even if other portions of the periphery ofthe lower electrode LE1 are located between the insulating layer 12 andthe partition 6, the same advantages as those of these embodiments canbe obtained. In the lower electrodes LE2 and LE3, too, the portionarranged between the insulating layer 12 and the partition 6 can beselected as appropriate. In addition, the entire periphery of the lowerelectrodes LE1, LE2, and LE3 may be located between the insulating layer12 and the partition 6.

All of display devices that can be implemented by a person of ordinaryskill in the art through arbitrary design changes to the display devicesdescribed above as embodiments of the present invention come within thescope of the present invention as long as they are in keeping with thespirit of the present invention.

Various types of the modified examples are easily conceivable within thecategory of the ideas of the present invention by a person of ordinaryskill in the art and the modified examples are also considered to fallwithin the scope of the present invention. For example, the aboveembodiments with addition, deletion, and/or designed change of theirstructural elements by a person having ordinary skill in the art, or theabove embodiments with addition, omission, and/or condition change oftheir processes by a person having ordinary skill in the art areencompassed by the scope of the present inventions without departing thespirit of the inventions.

In addition, the other advantages of the aspects described in theembodiments, which are obvious from the descriptions of the presentspecification or which can be arbitrarily conceived by a person ofordinary skill in the art, are considered to be achievable by thepresent invention as a matter of course.

What is claimed is:
 1. A display device comprising: a substrate; a pixelcircuit overlapping the substrate; an insulating layer on the pixelcircuit and including a contact hole; a first lower electrode and asecond lower electrode on the insulating layer and arranged in a seconddirection crossing at a right angle to a third direction normal to anupper surface of the substrate, the first lower electrode beingconnected to the pixel circuit at the contact hole; a first upperelectrode opposing the first lower electrode in the third direction; asecond upper electrode opposing the second lower electrode in the thirddirection; a first organic layer located between the first lowerelectrode and the first upper electrode and including a firstlight-emitting layer; a second organic layer located between the secondlower electrode and the second upper electrode and including a secondlight-emitting layer; a rib formed of a first inorganic material on thefirst lower electrode and the second lower electrode and including afirst pixel aperture overlapping the first lower electrode in a planview, and a second pixel aperture overlapping the second lower electrodein the plan view; a partition located between the first pixel apertureand the second pixel aperture in the plan view, the partition includinga lower portion on the rib, and an upper portion on the lower portionand extending beyond a side surface of the lower portion in the seconddirection, wherein the first light-emitting layer emits a light of afirst color, the second light-emitting layer emits a light of a secondcolor different from the first color, the first organic layer includes afirst portion in contact with the first lower electrode at the firstpixel aperture, and a second portion located on the partition and spacedapart from the first portion, the second organic layer includes a thirdportion in contact with the second lower electrode at the second pixelaperture, and a fourth portion located on the partition and spaced apartfrom the third portion, the lower portion of the partition includes afirst side surface and a second side surface, the first side surfacebeing closer to the first pixel aperture compared to the second sidesurface in the second direction, the rib includes a first step and asecond step located between the first lower electrode and the secondlower electrode in the second direction, the first step of the rib iscloser to the first lower electrode compared to the second step of therib in the second direction, and the first step and the second step arelocated between the first side surface of the lower portion of thepartition and the second side surface of the lower portion of thepartition in the second direction.
 2. The display device according toclaim 1, wherein in a cross-sectional view, the lower portion of thepartition overlaps the first step of the rib and the second step of therib.
 3. The display device according to claim 1, wherein in across-sectional view, the contact hole includes a contact area where thefirst lower electrode is electrically in contact with the pixel circuit,and the first step of the rib and the second step of the rib are locatedbetween the contact area of the contact hole and the second side surfaceof the lower portion of the partition in the second direction.
 4. Thedisplay device according to claim 1, wherein in a cross-sectional view,the first lower electrode includes a first edge, the second lowerelectrode includes a second edge, the first edge of the first electrodeis located between the first side surface of the lower portion of thepartition and the first step of the rib in the second direction, and thesecond edge of the second lower electrode is located between the secondside surface of the lower portion of the partition and the second stepof the rib in the second direction.
 5. The display device according toclaim 1, wherein the first upper electrode includes a fifth portion incontact with the first portion of the first organic layer and a sixthportion in contact with the second portion of the first organic layerand spaced apart from the fifth portion, and the second upper electrodeincludes a seventh portion in contact with the third portion of thesecond organic layer and an eighth portion in contact with the fourthportion of the second organic layer and spaced apart from the seventhportion.
 6. The display device according to claim 5, wherein the lowerportion of the partition is formed of a conductive material, the fifthportion of the first upper electrode is in electrically contact with thefirst side surface of the lower portion of the partition, and theseventh portion of the second upper electrode is in electrically contactwith the second side surface of the lower portion of the partition. 7.The display device according to claim 6, further comprising: in across-sectional view, a first sealing layer formed of a second inorganicmaterial and covering the fifth portion of the first upper electrode,the first side surface of the lower portion of the partition and thesixth portion of the first upper electrode, and a second sealing layerformed of a third inorganic material and covering the seventh portion ofthe second upper electrode, the second side surface of the lower portionof the partition and the eighth portion of the second upper electrode.8. The display device according to claim 1, wherein in a cross-sectionalview, the second portion of the first organic layer overlaps the firstside surface of the lower portion of the partition, and the fourthportion of the second organic layer overlaps the second side surface ofthe lower portion of the partition.
 9. The display device according toclaim 1, wherein in a cross-sectional view, an entirety of the secondportion of the first organic layer overlaps the first lower electrode,and at least a part of the fourth portion of the second organic layeroverlaps the second lower electrode.
 10. The display device according toclaim 1, wherein in a cross-sectional view, the contact hole includes acontact area where the first lower electrode is electrically in contactwith the pixel circuit, and the contact area of the contact hole islocated between the second portion of the first organic layer and thefourth portion of the second organic layer in the second direction. 11.The display device according to claim 5, wherein in a cross-sectionalview, the sixth portion of the first upper electrode overlaps the firstside surface of the lower portion of the partition, and the eighthportion of the second upper electrode overlaps the second side surfaceof the lower portion of the partition.
 12. The display device accordingto claim 5, wherein in a cross-sectional view, an entirety of the sixthportion of the first upper electrode overlaps the first lower electrode,and at least a part of the eighth portion of the second upper electrodeoverlaps the second lower electrode.
 13. The display device according toclaim 5, wherein in a cross-sectional view, the contact hole includes acontact area where the first lower electrode is electrically in contactwith the pixel circuit, and the contact area of the contact hole islocated between the sixth portion of the first upper electrode and theeighth portion of the second upper electrode in the second direction.14. The display device according to claim 1, wherein a thickness of therib is less than a thickness of the partition.
 15. The display deviceaccording to claim 1, wherein in a cross-sectional view and in the thirddirection, the rib and the partition each include a recess portionlocated above the contact hole.
 16. The display device according toclaim 15, wherein in the second direction, the recess portion of the ribis between the second portion of the first organic layer and the fourthportion of the second organic layer.
 17. The display device according toclaim 15, wherein in the second direction, the recess portion of thepartition is located between the second portion of the first organiclayer and the fourth portion of the second organic layer.
 18. Thedisplay device according to claim 7, wherein in the cross-sectionalview, the first sealing layer includes a third edge above the upperportion of the partition, the second sealing layer includes a fourthedge above the upper portion of the partition, and the third edge of thefirst sealing layer and the fourth edge of the second sealing layer arespaced apart from each other in the second direction.
 19. The displaydevice according to claim 18, wherein in the second direction, the thirdedge of the first sealing layer is located between the first sidesurface of the lower portion of the partition and the contact area ofthe contact hole.
 20. The display device according to claim 18, whereinin the second direction, the fourth edge of the second sealing layer islocated between the second side surface of the lower portion of thepartition and the contact area of the contact hole.